Phaeochromocytoma and hypertrophic cardiomyopathy: apparent suppression of symptoms and noradrenaline secretion by calcium-channel blockade.

A 44-year-old woman with hypertrophic cardiomyopathy and a noradrenaline-secreting phaeochromocytoma is described. She experienced as great improvement in cardiovascular symptoms during double-blind treatment with the calcium-channel blocker nifedipine compared with the placebo period. Symptom relief on nifedipine therapy was associated with a pronounced decline in elevated urinary noradrenaline levels. This observation suggests that calcium-channel blockers interfere with the release of noradrenaline from phaeochromocytoma tissue and thus may be beneficial in patients with phaeochromocytoma.